#pragma once

#include <iostream>
#include <cstdio>
#include <string>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <unistd.h>
#include "Comm.hpp"

const int gdefaultid = -1;
const int gsize = 4096;
const std::string pathname = ".";
const int projid = 0x66;
const int gmode = 0666;

enum class Type
{
    CREATER,
    USER,
};

class Shm
{
    private:
    void CreateHelper(int flg)
    {
        printf("key: 0x%x\n", _key);
        // 共享内存的生命周期，随内核
        _shmid=shmget(_key,_size,flg);
          if (_shmid < 0)
        {
            ERR_EXIT("shmget");
        }
        printf("shmid: %d\n", _shmid);
    }
    void Create()
    {
        CreateHelper(IPC_CREAT | IPC_EXCL | gmode);
    }
    void Get()
    {
        CreateHelper(IPC_CREAT);
    }
    void Attach()
    {
        _start_mem=shmat(_shmid,nullptr,0);
         if ((long long)_start_mem < 0)
        {
            ERR_EXIT("shmat");
        }
        printf("attach success\n");
    }

    void Detach()
    {
        int n=shmdt(_start_mem);
        if(n==0)
        {
            printf("detach success\n");
        }
    }

    void Destroy()
    {
        int n = shmctl(_shmid, IPC_RMID, nullptr);
        if (n > 0)
        {
            printf("shmctl delete shm: %d success!\n", _shmid);
        }
        else
        {
            ERR_EXIT("shmctl");
        }
    }
    public:
    Shm(const std::string &pathname, int projid, Type usertype)
    :_shmid(gdefaultid),
     _size(gsize),
     _start_mem(nullptr),
     _usertype(usertype)
     {
        _key=ftok(pathname.c_str(),projid);
         if (_key < 0)
        {
            ERR_EXIT("ftok");
        }
        if (_usertype == Type::CREATER)
        Create();
        else if (_usertype == Type::USER)
        Get();
        else{}

        Attach();
     }

    void *VirtualAddr()
    {
        printf("VirtualAddr: %p\n", _start_mem);
        return _start_mem;
    }

     void Attr()//打印内核数据结构
    {
        struct shmid_ds ds;
        int n = shmctl(_shmid, IPC_STAT, &ds); // ds:输出型参数
        printf("shm_segsz: %ld\n", ds.shm_segsz);
        printf("key: 0x%x\n", ds.shm_perm.__key);
    }

    ~Shm()
    {
        Detach();
        if(_usertype == Type::CREATER)
        Destroy();
    }

    private:
    int _shmid;
    key_t _key;
    int _size;
    void *_start_mem;
    Type _usertype;
};